Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

• Beatriz Dedeiras,
• Catarina S. Caldeira,
• José C. Cunha,
• Clara S. B. Gomes and
• M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

• functionalized thiols (aromatic, aliphatic, and heterocyclic) were chosen to produce the β-sulfinyl esters 4 (Scheme 3). We next investigated the electrophilic amination reaction (Scheme 4). First, different functionalized β-sulfinyl esters were reacted with BBX 2a. For the aromatic and pyridine moieties, the

Intramolecular C–H arylation of pyridine derivatives with a palladium catalyst for the synthesis of multiply fused heteroaromatic compounds

• Yuki Nakanishi,
• Shoichi Sugita,
• Kentaro Okano and
• Atsunori Mori

Beilstein J. Org. Chem. 2024, 20, 3256–3262, doi:10.3762/bjoc.20.269

• % yield, respectively. The related reaction is also carried out with amides of non-pyridine derivatives terephthal- and benzamides to afford multiply fused heterocyclic compounds in 81% and 89% yields, respectively. Keywords: intramolecular C–H arylation; multiply fused heterocycles; palladium acetate

• efficiencies in atom economy [3][4]. The extension of the reaction to an intramolecular version represents a viable approach for the construction of several fused-ring skeletons [5]. Such ring structures containing heterocyclic rings would be of crucial importance because heterocycle-fused ring structures [6

• [30][31][32]. We herein report the palladium-catalyzed intramolecular C–H arylation of several pyridine and non-pyridine amides to afford multiply fused heterocyclic compounds. Results and Discussion First, we started with the synthesis of the cyclization precursors 1a–c that was carried out by the

Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

• Sergio Torres-Oya and
• Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

• construction of carbon–carbon bonds [5][6][7][8][9][10]. The hetero-Diels–Alder reaction is therefore an attractive strategy for the synthesis of heterocyclic compounds. It involves the reaction of dienes or dienophiles which possess a heteroatom in their structure. In this reaction, the HOMO of the diene and

• the LUMO of the dienophile interact to construct the six-membered heterocyclic derivative and the reaction requires electron-rich dienes and electron-poor dienophiles (Figure 2a). In the inverse electron demand hetero-Diels–Alder reaction (IEDHDA), the LUMO of the diene interacts with the HOMO of the

• dienophile, and therefore it proceeds through the reaction of electron-poor dienes and electron-rich dienophiles (Figure 2b). α,β-Unsaturated imines can undergo inverse electron demand aza-Diels–Alder reactions (IEDADA) to produce N-heterocyclic compounds. The search for an enantioselective pathway to carry

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• synthesis of tripeptides incorporating new fluorinated heterocyclic hydrazino acids, based on the tetrahydropyridazine scaffold is described. Starting from simple fluorinated hydrazones, these non-proteinogenic cyclic β-amino acids were easily prepared by a zinc-catalyzed aza-Barbier reaction followed by an

• ; Introduction The synthesis of molecules capable of mimicking the various secondary structures and key functions of proteins is a major challenge in medicinal chemistry, especially in the fields of protein–protein interactions [1][2]. Accordingly, the incorporation of heterocyclic amino acids into peptides

• strategy, the control of the stereoselectivity of the intramolecular aza-Michael addition could be envisaged with various chiral catalysts in further studies. These heterocyclic hydrazino acids, when incorporated into the peptidic structure, appear to confer an extended conformation. These interesting

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• synthesizing diverse scaffolds [6]. Furthermore, the Ugi reaction exhibits versatility in forming both fused and unfused heterocyclic compounds, involving 4-, 5-, 6-, and 7-membered rings [17]. This capability is exploited by various approaches, including the Ugi–Deprotection–Cyclization strategy (UDC) and

• heterocyclic core. The novel compounds were first evaluated using β-arrestin recruitment assays in CHO (chinese hamster ovary) cells overexpressing human GPR55. These new compounds have been evaluated in competitive binding assays for cannabinoid receptors, but all of them showed to be selective for GPR55 (>4

• heterocyclic scaffold is subsequently formed [58]. In 2015, Xu et al. [59] reported the synthesis of 1,5-benzodiazepines using the UDC approach. The process begins with Ugi-4CRs, incorporating amines, glyoxaldehydes, 2-(N-Boc-amino)phenylisocyanide, and carboxylic acids. Following this, the Boc group is

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• ; heterocycles; hypervalent iodine; oxidation; Introduction Halogenated carbocyclic and heterocyclic compounds are present in many active pharmaceutical ingredients [1][2]. The intramolecular halocyclisation of alkenes mediated by HVI(III) reagents allow access to a range of halogenated cyclic scaffolds in a

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• (aromatic) organic heterocyclic systems, excluding calix[4]pyrroles, which are colorless and non-aromatic, as well as norcorroles, isophlorins, and the 16π oxidized form of porphyrin that exhibits anti-aromatic character (Figure 1a). Calix[4]pyrroles possess a nonplanar structure and a high degree of

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• ; isocyanides; MCF-7 cell line; methanesulfonylindoles; Ugi-azide reaction; Introduction Nitrogen-containing heterocyclic moieties, such as 1,5-disubstituted tetrazoles and indoles, are considered pharmacophoric fragments due to their pivotal interactions with several targets involved in many diseases. They

• synthesis of a novel bis-heterocyclic hybrid, 1,5-disubstituted-tetrazole-indoles. The compounds were achieved through a high-order multicomponent reaction consisting of two sequential processes: an Ugi-azide reaction and a further Pd/Cu-catalyzed heteroannulation (Scheme 1d). Results and Discussion Our

• -heterocyclic system [23], involves a two-step sequence starting with an Ugi-azide multicomponent reaction, followed by a Pd/Cu-catalyzed heteroannulation process, as depicted in Scheme 2. Conditions for the Ugi-azide reaction were optimized based on our recent findings, i.e., the reaction was performed in

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• of α-fluoroacetoacetamides 5 utilising unsymmetric DIAS 6. Various α-fluoroacetoacetamides 5 with electronically different aliphatic, aryl ring, and heterocyclic substitutions were discovered to be easily arylated using this method. The products were obtained within 30 minutes in the presence of

Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions

• Marzieh Norouzi,
• Mohammad Taghi Nazeri,
• Ahmad Shaabani and
• Behrouz Notash

Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241

• great attention in biomedical applications, clinical diagnostics, and conjugate materials. Keywords: cyclic imines; dibenzothiazepine; dibenzoxazepine; isocyanides; multicomponent reactions; pyrrole; triazolobenzodiazepine; Introduction Pyrroles and their derivatives are important N-heterocyclic

• olefins and isocyanides (Scheme 4). As expected, under almost the same conditions as described in Scheme 3 (only at 80 °C), a new type of heterocyclic compounds, pyrrole-fused triazolobenzodiazepines, was obtained in high yield. As summarized in Scheme 4, a variety of gem-diactivated olefins with electron

Synthesis of tricarbonylated propargylamine and conversion to 2,5-disubstituted oxazole-4-carboxylates

• Kento Iwai,
• Akari Hikasa,
• Kotaro Yoshioka,
• Shinki Tani,
• Kazuto Umezu and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2024, 20, 2827–2833, doi:10.3762/bjoc.20.238

• -acylamine; oxazole; propargylamine; Introduction Propargylamine is an important motif in the synthesis of heterocyclic compounds [1][2][3][4] and drug discovery [5][6] due to its multifunctionality, which includes a basic and nucleophilic amino group, an electrophilic and dipolarophilic triple bond, and an

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• Chemistry Department, RUDN University, 6 Miklukho-Maklaya St., 117198 Moscow, Russian Federation 10.3762/bjoc.20.236 Abstract The heterocyclic core of imidazo[1,2-a]pyrimidine was formed in satisfactory yields as a result of the interaction of the readily available 2-aminoimidazole with N-substituted

• in clinical use, suggest that they may possess antifungal activity against Candida albicans. Keywords: 2-aminoimidazole; antimycotic activity; imidazo[1,2-a]pyrimidine; molecular docking; N-arylitaconimides; N-substituted maleimides; recyclization; Introduction Nitrogen-containing heterocyclic

• polysubstituted hydrogenated heterocyclic structures on their basis [25][26][27][28], including an acetanilide fragment. The introduction of this fragment into a molecule, often drugs, enhances the cytotoxic, antibacterial, and antiviral activity of the compounds, thus widening the range of their potential

Mechanochemical difluoromethylations of ketones

• Jinbo Ke,
• Pit van Bonn and
• Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

• -depleting sulfur dioxide as side products [46][47]. Later, Ichikawa and co-workers established the release of difluorocarbene from TFDA with catalytic amounts of an N-heterocyclic carbene and a base (Scheme 1C) [29][48][49]. In these reactions, difluoromethyl enol ethers were obtained, which were

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• porphyrins, achieved porphyrins 32 and 33 in a 47% and 56% yield, respectively (Table 1, entries 13 and 21), using Cs2CO3 as the base. Electron-withdrawing sulfur-containing heterocyclic substrates 21 and 23 do not readily undergo protodeboronation even at high pH [44][47] making the yields of porphyrins 31

• -analogue porphyrin 35. Use of the electron-donating p-tolylboronic acid (20), resulted in a 30% yield (Table 2, entry 12) again requiring an increase of catalyst loading and a change of base to K3PO4. Heterocyclic boronic acids/esters were again investigated for coupling reactivity with a consistent trend

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• Francesco Gambuti Jacopo Pizzorno Chiara Lambruschini Renata Riva Lisa Moni Department of Chemistry and Industrial Chemistry, University of Genoa, Via Dodecaneso 31, 1646 Genova, Italy 10.3762/bjoc.20.230 Abstract Spiro-heterocyclic indolenines are privileged scaffolds widely present in numerous

• -indolenines, specially the spiro-heterocyclic indolenines, can be considered as a privileged scaffold, present in several natural products with interesting biological activities, as depicted in Figure 1 [4][5][6][7]. Among the known methods of synthesizing spiro-heterocyclic indolenines, the dearomative

• spiro-heterocyclic indolenines from readily available starting materials under mild conditions and in a diversity-oriented fashion remains desirable. In this contest, oxidative isocyanide-based multicomponent reactions (oxidative IMCRs) can be considered as a convenient tool [15]. Actually, the use of

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• respective cyclisation product. Hence, the application of the reaction conditions to starting materials 4b, 4c and 4e resulted in the decomposition of the starting materials and no product could be isolated. The employment of heterocyclic benzothiophene gave a very good yield of 80% for product 5i. Optical

5th International Symposium on Synthesis and Catalysis (ISySyCat2023)

• Anthony J. Burke and
• Elisabete P. Carreiro

Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227

• Suzuki couplings and the reduction of the thiazole moiety to 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a crucial intermediate, using BH3⋅NH3 and tris(pentafluorophenyl)borane as a Lewis acid, followed by treatment with formic acid. Gillie et al. reported the synthesis of a laterally fused N-heterocyclic

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• Alfiya R. Gimadieva Yuliya Z. Khazimullina Aigiza A. Gilimkhanova Akhat G. Mustafin Ufa Institute of Chemistry at Ufa Federal Research Center, Russian Academy of Sciences, 71 prosp. Oktyabrya, 450054 Ufa, Russian Federation 10.3762/bjoc.20.219 Abstract Nitrogen-containing heterocyclic compounds

• convenience of the process, our objective is to enhance the efficiency of the Elbs and Boyland–Sims peroxydisulfate oxidation reactions. Results and Discussion We conducted research to enhance the product yield of peroxydisulfate oxidation reactions of specific nitrogen-containing heterocyclic compounds, such

• overoxidized and leads to destruction of the heterocyclic ring. As a result, the yield of the final products decreases. Furthermore, oxidation is incomplete at temperatures lower than the optimal temperature. The oxidation of MU (1), TMU (4), and pyridine (7) using ammonium peroxydisulfate (APS) was conducted

Synthesis and cytotoxicity studies of novel N-arylbenzo[h]quinazolin-2-amines

• Battini Veeraiah,
• Kishore Ramineni,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Hélène Solhi,
• Rémy Le Guevel,
• Chada Raji Reddy,
• Frédéric Justaud and
• René Grée

Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218

• attractive results in this area. Keywords: Buchwald–Hartwig coupling; cytotoxicity; heterocycles; Pd catalysis; quinazolines; Introduction Nitrogen-containing heterocyclic molecules are ubiquitous in living systems. Among them, quinazolines, and especially the 4-aminoquinazolines (type A molecules, Figure

• ) exhibited a relatively broad cytotoxicity on four cancer cell lines among the seven assayed. On the other hand, two others (4f and 4h) were active only on Caco-2, while another one (4d) only on HCT-116. Thus, the results obtained with these compounds indicate that such a novel heterocyclic scaffold, which

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• ; 1,1′-carbonyldiimidazole; 3-hydroxypyran-4-ones; tetronic acid; Introduction 3-Hydroxypyran-4-one derivatives are an important class of heterocyclic compounds widely represented in various naturally occurring sources [1][2][3][4]. Products of this type demonstrate a broad range of biological activity

• unit and a nucleophilic fragment in the side chain various transformations are possible. For example, a pyranone ring can be opened and recyclized into the novel heterocyclic system. Indeed, previously we have shown that various allomaltols 1 containing a hydrazide moiety are converted into substituted

Photoredox-catalyzed intramolecular nucleophilic amidation of alkenes with β-lactams

• Valentina Giraldi,
• Giandomenico Magagnano,
• Daria Giacomini,
• Pier Giorgio Cozzi and
• Andrea Gualandi

Beilstein J. Org. Chem. 2024, 20, 2461–2468, doi:10.3762/bjoc.20.210

• -centered radicals, such as aminyl, amidyl, or iminyl radicals, N-heterocyclic amidyl radicals were largely underinvestigated despite their importance as intermediates or relevant N-heterocyclic products in medicinal chemistry [7][8][9][10]. Recently, photoredox catalysis has emerged as a novel area of

• ]. Through tailored molecular design, it is possible to enhance the oxidation capability of these catalysts, enabling the utilization of less reactive alkenes and even aromatic molecules such as toluene [32]. Until now, heterocyclic amides such as β-lactam compounds have not been employed in alkene

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

• Dominik L. Reinhard,
• Anna Schmidt,
• Marc Sons,
• Julian Wolf,
• Elric Engelage and
• Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

• that six-membered core structures are also weaker XB donors (iodininium 3OTf) than iodolium 1OTf [13]. Furthermore, the importance of substituents in the core and on the outer rings was demonstrated (XB donors 2OTf and 4OTf). Nachtsheim reported the synthesis of N-heterocyclic substituted monocationic

• donors [16][17] from our group as well as of dicationic N-heterocyclic-substituted monodentate catalysts by Nachtsheim [15]. While such compounds are necessary to activate neutral substrates in more challenging reactions, monodentate and monocationic congeners provide sufficient activation in halide

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• , Leninskii prosp., 31, 119991, Moscow, Russia Institute of Inorganic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany 10.3762/bjoc.20.202 Abstract A series of new RS−, RS−CH2− and R2N−CH2-functionalized сatechols with heterocyclic fragments such as 1,3,4-oxadiazole, 1,2,4

• -triazole, thiazole, or pyridine were synthesized by the reaction of 3,5-di-tert-butyl-o-benzoquinone or 3,5-di-tert-butyl-6-methoxymethylcatechol with different heterocyclic thiols. The S-functionalized catechols were prepared by the Michael reaction from 3,5-di-tert-butyl-o-benzoquinone and the

• established for these compounds. The electrochemical behavior of the studied compounds is influenced by several factors: the nature of the heterocycle and its substituents, the presence of a sulfur atom in the catechol ring, or a thione group in the heterocyclic core. The radical scavenging activity and

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• tool for the rapid construction of medicinal chemistry-relevant heterocyclic homoallylic amines in an enantioselective manner without involving nucleophilic allylation. The highly functionalised products offer the possibility of further derivatisation. Other catalytic approaches In 2017, the

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

• Yuri A. Sidunets,
• Valeriya G. Melekhina and
• Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

• Federation 10.3762/bjoc.20.200 Abstract A straightforward protocol for the synthesis of a previously unknown [1,2,5]oxadiazolo[3,4-d][1,2,3]triazin-7(6H)-one heterocyclic system was developed. The described approach is based on tandem diazotization/azo coupling reactions of (1,2,5-oxadiazolyl)carboxamide

• derivatives bearing both aromatic and aliphatic substituents. The NO-donor ability of the synthesized furoxano[3,4-d][1,2,3]triazin-7(6H)-ones was additionally evaluated. The elaborated method provides access to novel nitrogen heterocyclic compounds with potential applications as drug candidates or

• , anticancer, non-steroidal anti-inflammatory, antihypertensive, antipsychotic, anxiolytic and in other pharmaceuticals [3][4][5]. Therefore, considering the diversity of biological properties, development of reliable approaches for the synthesis of new nitrogen heterocyclic systems is a highly urgent goal